Pneumatic grease gun



Jan. 3,1, 1928.

C. G. COOPER ET AL PNEUMATIC GREASE GUN 2 Sheet l Filed June 15, 1925 TOR'. w74 m Jan. 31, 1928.

t n, 5 .m n0.. .w l e e h S 2 L Ams TG@ RA. Emw w n CU OHJ CAd .Me U1 GEi .WF C

Patented Jan. 31, 1928.

Latina Parrau'r orifice..

CHARLES of. coornn nnnnnnnnw a. Dinner, on Yuma, numana.

PNEUMAIIG GREASE GUN.

Application filed .Tune 15, 1925. Serial No. 37,191.

i Our `invention relates to devices for t'orc ing lubricating grease into bearings of engines and other machinery, the objects being, lirst, to provide a grease gun which is voperated by fluid pressures, second, to pro vide in such a device means for developing, from a moderate fluid pressure, a very high pressure upon the grease, third, to provide a grease gun, operated by iiuid pressure, with means forV using the pressure exerted against the grease in its simple power and also, when greater pressure is required, to

compound the power exerted upon the grease. The present invention is more particularly adapted to inject very hard grease into the bearings` ol locomotives, and a fourth object is to provide a grease gun which can be operated by air Jfrom the air compressor of the locomotive to force grease into its bearings. Withrei'erence to the accompanying drawings: f

Fig. 1 is a longitudinally sectioned eleva. tion ofthe entire device. Y

Fig. 2 is a group iigure showing certain parts required to transform the invention lrom a simple to a compound gun.

Fig. 3 is a top view ot the entire device. Fig. A is a view in side elevation of a valve element for controlling the operation of the device, the view being taken in the direction ol' the arrow A Fig. 3.`

ldig.y 5 is a..perspective view of a stick of grease such as is ed to the gun.

More -specilically the present invention comprises an actuating cylinder 1 provided with a head 2, in an extension ol which is termed a low pressure plunger cylinder 3,.

havinga cap Il, and a head in which is Vformed a packing gland 6 having packing Y and a follower 8. Anelement 9 is screwed into the packing gland 6 against thefollower 8 and forms a high pressure plunger cylin der on the outer end of which a union 1 0 and discharge tube 11 is screwseated. The discharge tube 11 is here shown as a flexible metallic tube but it may be formed of solid metal tubing with swing joints and in either case it is provided at its outer end with adequate means lor connecting itto the lixture mounted upon the bearing to whichv grease is applied. l f

A plunger element is provided for the cylinders having a. low pressure end 12slid ably mounted in the low pressure cylinder 3 and a high pressure` end 13 shdably mounted in the high pressure cylinder 9. rlhe plunger element is developed in its interior by boring in from the high pressure end to a point near the low pressure end, then boring in from the low pressure end with a drill of larger dia-meter sufficiently deep to leave a solid section 1d. The section la is then provided with several small holes l5 to allow for the passage ot grease and a central bore in which is slidably mounted the valve stem 16 otavalve 17. A plug 18 is screw seated in the bore of the low pressure `end having a central orilice against which the valve l( orms closure as shown.

Atthe center between the high and low pressure ends of the plunger element a piston for the actuatingcylinder is mounted comprisinga couplet of plates 19, 19 between which-a pair of oppositely faced cup leathers 20, 2O are carried, the plates and cup leathers being held iirmly in position by the two nuts 21. y

A valve for operating the cylinder 1 may be constructed lilre that` shown in Figli in which 22 represents a body member and 23 a rotatably mounted plug having a handle 2e.' The plug 23 carries a curved port 25 and a second curved port 26 and the body member carries an inlet port 27,. a discharge port 28, a port 29 for the right hand end of the cylinder and a port 30 for the left hand `end of the cylinder. `When the l `valve is mounted on the cylinder l as shown in Fig. 3 the ports 29 and 30 match with Yholes bored in the members 3l and 32 re spectively, whereby air may flow intoand out ,of each end ot the cylinder 1. In the operation of the valve with the handle in the position shown in Fig. 4c air is admitted to the right hand end of .the cylinder through inlet port 27 port 26 and port 29 and at the same time air may flow outpof the left hand end of the cylinder through ports 30, 25 and 28. lilith the handle thrown to the left port 27 connects with ports 26 and 28. Thus air `is admitted to the left hand end of the cylinder and discharged from the right hand end. Y

A tubular feed hopper 33 is mounted upon the low pressure plunger cylinder 3 and in opwen communication with its interior, the` hopper being adapted to receive balls of `grease Silas shown in Fig. 1 `or a stick of grease as shown in Fig. 5. y

In the operation oi, the present invention the hopper 33 is loaded with hard grease, the y tube 1l is connected with the vfitting of the bearing to be greased and air is admitted, by hose connection With a source of pressure supply, tothe inlet 27. The handle 24 is then moved to the left causing the piston to move to the right thus compressing a ball ot grease represented by the bottom dotted circle 34. This grease is forced back through the valve 17 and the bores in the plungers l2 and 13. -When the piston has made a full stroke to the right the handle 24 is thrown to the right and the piston and plungers move to the let't allowing another ball ot grease to fall into the low pressure plunger vcylinder the handle 2d is again thrown to the lett compressing the second ball ot grease and so on until the grease has filled into the high pressure plunger cylinder. When the grease has lilled into the high pressure cylinder the piston et the actuating cylinder on moving to the lett now compresses thegrease a second time through the plunger i3 thus forcing it out through the tube 1l. The operation et the device may be discontinued by moving the handle 24 to a vertical position.

More pressure is usually required to torce the grease out through the tube ll and into a bearing than to torce the grease trom the loW pressure cylinder into the high pressure cylinder Atherefore the low pressure plunger should have more than twice the area ot the high pressure plunger. The diameters ot' the plungers and the length of the stroke lare so proportie-ned that the volume of grease 'compressed through the lastv part ot the stroke of the low pressure plunger-'Will be about sutlicient to completely till the high pressure cylinder throughout the length et the stroke. lt! is admitted that a vacuum i's created in both plunger cylinders through a part of the backward stroke but the power ofthe actuating cylinder is sullieient to overcome such a vacuum on the small areas and also compress the grease. lt is intended that a check valve shall be'mounted on the itting of eachV bearing thus preventing the grease from being drawn back into the high pressure `cylinder through the tube 11 and the 'valve 17 'performs the same oliice for the lciv pressure cylinder.

1lll/'hen climatic conditions are favorable "aste temperature or when the grease used 'is sutliciently sott the gun herein shown may be used in a simple term instead of compound form as hereinbefore described. To change the gun into a simple acting device the cap et is removed, the plug 18 is screwed out and a solid plug 3a- (see Fig. 2) is screwed into its place. n cap having discharge conduit 36 is screwed on in place 'of the cap 4. With these changes the gun will operate vonly on the loir pressure end to discharge grease out through the "conduit v36, the plunger 13 in such an arnomme rangement only acting as a sliding guide.

lWhile air has been menliruied herein as the actuating fluid it is to be understood that the device vfill operate equally as niell with other fluids under pressure.

The exact torni o'l the means 'tor charging grease into the gun and oit the valve tor operating the actuating cylinder lforms no part ot our present invention, and it is to be understood that many changes might be made in the invention as shown Without departing trom the spirit thereof as claimed.

llaiving thus described our invention, We claim:

l. fr grease gun comprising a high pressure cylinder and a lov.' pressure cylinder, a plunger reciprocable in both ol'i the cylinders a passage in the plunger to establish communication between the cylinders, means tor supplying grease to the low pressure cylinder, means tor reciprocating the plunger to 'temporarily cut oli' the grease supply means and place the grease under pressure when the plunger is moved in one direction and thus torce the grease through the passage to the high pressure cylinder', and means operable `when the plunger is moved in the opposite direction to cheek the grease in the par-sage against being returned to the lon'v pressure cylinder so as to cause the grease to accumulate in the passage and thus co-act with the high pressure end ot the plunger in liorming a piston. tor ejecting grease Yiirom the high pressure cylinder under a pressure greatly e.\;ceeding the pressure in the lon' pressure c 7linder.

2. il. grease gun as embodied in claim l, `wherein the grease supply means includes a port in coinnnmication with the low pressure cylinder during a part ot the stroke o' the plunger in the lirst mentioned direction, so as to admit a charge of grease to the cylinder, and during the remainder et the stroke to be closed by the plunger so that the charge is placed under pressure by the plunger.

3. nl grease gun embodied in claim l, wherein the grease checking means comprises a valve at the loiv pressure end of the plunger which is yieldably urged to closed position.

1l. fr grease gun as embodied in claim l, wherein the grease checking means comprises a valve in the plunger which is yieldably urged to closed position, and the grease supply means :includes a port in con'nnunicution with the lov.' pressure cylinder during a part ot' the stroke et the plunger in the lirst mentioned direction so as to admit a charge ot grease to the cylinder und during the remainder ol the stroke to be closed so that the charge is placed under pressure by the plunger.

5. A grease gun as embodied in claim l, wherein the grease checkingl means comlili prises a Valve in the plunger which is yield ably urged to closed position, and the grease supply means includes a port in communication with the 10W pressure cylinder during a.

part of the stroke of the plunger in the rst mentioned direction so as to admit a charge of grease to the cylinder and during the remainder of the stroke to'be closed by the plunger so that the charge is placed under pressure by the plunger, and a removable 10 cap for the 10W pressure cylinder.

In testimony whereof we have signed our naines to this specification.

CHARLES G. COOPER. ANDREW J. DIN KEL. 

